How are you sure that the sample is really pure ThO2? 96% pure sounds pretty good. Are there no other elements present? What does EDS or a wavescan show? If
they show nothing, and if there are no invisible elements (e.g., H), then I suppose you could declare it was really 100% pure.
The fact that your standard measures again at 96% shows the repeatability of your process. It looks like you are being consistent.
Under the Solaris version of the JEOL software, there is a way to go in and edit the standard data. If you were to set the standard intensity to 96.1% of what
it is currently, you should be able to reanalyze (or reprocess) the current data so that the standard comes up as 100% ThO2. (There may also be a way to change the composition of the standard back to 100%, but I have never tried to do that.)
However, I would be very careful to make sure that the action is justified. It would be erroneous to define your standard as pure if it really is not.
From: JEOL-Focused Probe Users List [mailto:[log in to unmask]]
On Behalf Of Fernando Colombo
Sent: Friday, October 14, 2016 8:12 AM
To: [log in to unmask]
Subject: [PROBEUSERS] problem with Th standard
Some time ago I analyzed monazite. Later, when checking the .cor file, I found in the "Standard data" section that the ThO2 concentration was listed
as 96.1180 (mass %). Since I am using a pure ThO2 standard, first I thought that I had entered the wrong numbers in the Standard Manager screen. However, after checking it, it was correct (100.00 % ThO2). When I analize the Th standard as an unknown, I do
get about 96% ThO2.
Any suggestion on how to correct this (other than multiplying the ThO2 result by 100/96.118) will be most appreciated.
LAMARX - Universidad Nacional de Córdoba
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